Rod memory solenoid weaving construction

ABSTRACT

A memory array comprised of a plurality of parallel bistable magnetic rods, arranged upright in rows and columns of a plane, and a solenoid weaving pattern of insulated conductive wires woven perpendicular to the rods and from rod to rod of each column and of each row. A solenoid is formed about the magnetic rods by a first wire passing adjacent rods on opposite sides and a second wire woven in the same manner as the first, except that it passes by each rod on the opposite side of the first. A plurality of first coordinate drives are formed by the solenoid wires woven about the rows of rods and a plurality of second coordinate drives are formed by the solenoid wires woven about the columns of rods, so that a different combination of first and second coordinate drives is formed by the solenoid weaving pattern for each rod.

United States Patent [72] inventor Donal A. Meier lnglewood,Cnlil. [21]App], Nov 786.224 221 Filed Dec.23, 1968 I231 Division of Ser. No.477.794. Aug. 6. 1965,

Pat. No. 3.440.719

July [3, 1971 The National Cash Register Company Dayton, Ohio [45)Patented [731 Assignee [54] R01) MEMORY SOLENOID WEAVING CONSTRUCTION 9Clallne, ll Drnwlng Figs.

[50] Field of Search (56] 7 References Clted UNITED STATES PATENTSPrimary Examiner- Stanley M. Urynowicz, Jr. Attorney: Louis A. Kline andJoseph R. Dwyer ABSTRACT: A memory array comprised of a plurality ofparallel bistable magnetic rods, arranged upright in rows and columns ofa plane, and a solenoid weaving pattern of insulated conductive wireswoven perpendicular to the rods and from rod to rod of each column andof each row. A solenoid is formed about the magnetic rods by a firstwire passing adjacent rods on opposite sides and a second wire woven inthe same manner as the first, except that it passes by each rod on theopposite side of the first. A plurality of first coordinate drives areformed by the solenoid wires woven about the rows of rods and aplurality of second coordinate drives are formed by the solenoid wireswoven about the columns of rods. so that a different combination offirst and second coordinate drives is formed by the solenoid weavingpattern for each rod.

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HIS ATTORNEYS ROD MEMORY SOLENOID WEAVING CONSTRUCTION This is adivision of copending US. application Ser. No. 477.794, filed Aug. 6,I965 now Pat. No. 3,440,719.

This invention relates generally to magnetic memories, and moreparticularly to improvements in rod memories of the type illustrated,for example, in US. Pat. No. 3,l34,965, issued May 26, I964 and Pat. No.3,228,012, issued Jan. 4, 1966.

In the magnetic memories disclosed in the aforementioned patents, anarray of suitable interconnected solenoids is provided with magneticrods passing through bores in the solenoids. Each rod has a rodlilteinner conductive substrate on which is suitably deposited on a thin filmmagnetic coating having bistable magnetic switching properties, adiscrete portion of which is capable of being switched from either stateto the other in response to current applied to the solenoidsrespectively coupled thereto. The importance of such a magnetic memoryconstruction and arrangement resides not only in the case of fabricatingrelatively compact high density magnetic memories, but also, in the veryhigh speed switching capability of such memories achieved because,unlike other known memory constructions and arrangements (such as thoseusing twistors"), these rod memories as disclosed in the aforementionedpatent and application permit the use of rods with thin magnetic filmsof less than l0,000 Angstroms.

Although such rod memories as disclosed in the aforementioned patent andapplication permit the construction of relatively compact high speed rodmemory structures, the increasing emphasis on size reduction hasresulted in acontinuing search for means and methods for constructingeven more compact rod memories, while at the same time maintaining, andif possible, improving their performance characteristics. It is towardsthese ends that the present invention is directed.

Accordingly, it is the broad object of this invention to provideimproved rod memory construction methods and arrangements whereby asignificantly more compact memory construction can be achieved.

A more specific object of this invention is to provide an improved rodmemory construction whereby one or more solenoid windings are providedfor each of a plurality of magnetic rods in a manner which permits a rodarray of high density to be obtained.

Another object of this invention is to provide an improved windingconstruction for the rod memory system disclosed in the aforementionedcopending patent application and patent, whereby significantly higherrod density arrays can be achieved.

A further object of this invention is to provide a magnetic memory, inaccordance with the foregoing objects, which provides a high density rodarray as well as being capable of better noise cancellation and fasteroperation.

Briefly, the above objects are accomplished, in accordance with thepresent invention, by substituting for the individual separately formedsolenoid windings in each array disclosed in the aforementioned patentand application, a solenoid weaving pattern in which the solenoids andthe interconnections therebetween are formed for a particular group ofrods together, each rod solenoid being formed one portion at a time. Theweaving pattern is such that each rod is provided with the desirednumber of solenoids having the desired number of turns in each solenoid,while at the same time permitting a high density rod array to beobtained.

The specific nature of the invention, as well as other objects, uses andadvantages thereof will become apparent from the following descriptionof the invention taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a pictorial view, in disassembled relationship, of a rod arrayhaving a solenoid weaving pattern formed thereon in accordance with theinvention.

FIG. 2 is a pictorial view illustrating a typical magnetic rod.

FIG. 3 is a diagrammatic illustration of the solenoid weaving techniqueof the invention as applied to a single row.

FIG. 4 is a fragmentary view of a woven solenoid rod array. having amultiturn row solenoid and a multitum column sole-- noid formed at eachrod position using the solenoid weaving; technique of the presentinvention.

FIG. 5 is a pictorial view illustrating a typical row in the array ofFIG. 4.

FIG. 6 is a pictorial view illustrating how two separate solenoidweavings can be provided in a row of a rod array in accordance with theinvention.

FIG. 7 is a plan view illustrating how a solenoid weaving pattern can beprovided for a digit plane of a rod array.

FIG. 8 is a pictorial view illustrating one way of providing a multiturnsolenoid at each rod position in the array of FIGS. 7, 9 and I0.

FIGS. 9 and 10 are plan views illustrating two ways of providing asolenoid weaving pattern for a digit plane of a rod array suitable foruse in obtaining common mode rejection.

FIG. 11 is a view illustrating how a three-dimensional rod memory matrixcan be provided employing solenoid weaving in each array in accordancewith the invention.

Like numerals designate like elements throughout the figures of thedrawings.

Referring initially to FIG. 1, illustrated therein, in disassembledrelationship, is a solenoid weaving pattern for a rod array inaccordance with the invention. Although only a relatively small numberof rods are illustrated in FIG. I, it will be understood that the arraymay be as large as desired. Also, the spacing between rows and columnsin FIG. I is exaggerated for the sake ofclarity.

Typically, fabrication begins with the provision of a support in theform of a plate 10 of suitable material upon which the solenoid weavingpattern is to formed. The plate 10 is provided with an array ofapertures 100, each aperture being spaced, dimensioned, and adapted toreceive a respective one of rigid pins 15a fixedly mounted in asupporting plate 15. The pins 15a are of sufficient length and sodisposed as to extend through respective ones of the apertures 10a andprotrude above the upper surface of plate 10 when the two plated l0 and[5 are brought into juxtaposition. Pins 15a are thereby permitted toserve as dummy rods or mandrels about which the solenoid weaving patternmay be formed. The solenoid weaving pattern may then be cemented orotherwise affixed to plate 10, after which the pins 15a can be removed,and the magnetic rods 12 inserted in their place. The magnetic rods 12may be cemented to retain them in place, or else, strips or a sheet ofadhesive film I6 may be applied to the lower face of plate It} forretention of the magnetic rods.

The specific nature of a typical magnetic rod 12 is illustrated in FIG.2, it being understood that the present invention is also applicable toany other type of rod memory where the features of the present inventionmay be used to advantage. The rod I2 comprises an inner conductivesubstrate which may typically be a beryllium copper rod of about 0.010inch in diameter, but preferably less than 0.050 inch, on which iselectrodeposited a thin bistable magnetic film 12b which may typicallybe a film of 97 percent iron and 3 percent nickel with a thickness of10,000 Angstroms or less. The bistable magnetic thin film lZb may alsobe a bilayer film of the type disclosed in Pat. No. 3,2l3,43l issuedOct. 19, 1965 -namely, a first adherent iron-nickel layerelectrodeposited on the beryllium copper rod 120 and composed of fromabout 30 percent to 90 percent nickel and from about 70 percent to 10percent iron, and a second adherent iron-nickel layer electrodepositedon the first layer and composed of from about 93 percent to 99 percentiron and from about 7 percent to l percent nickel, the compositethickness typically ranging from about 2,000 to 5,000 Angstroms.

The solenoid weaving pattern illustrated in FIG. I will now beconsidered in detail along with FIGS. 3 and 4. It will be understoodthat an insulated conductive wire 18 is employed for weaving. In weavinga particular row (or column), the wire 18, beginning with a respectiveguide pin 19, is woven back and forth between the dummy pins (which areultimately replaced by rods I2 as described previously) until the end ofthe row (or column) is reached, as illustrated by the solid line in FIG.3. This produces the equivalent of a one-half solenoid turn for each rodposition. Then, by bringing the wire I8 around the last pin at the endof the row in the reverse direction, as shown by the dashed line in FIG.3, the weaving pattern shown in FIG. I is obtained for each row (orcolumn), producing the equivalent of a one-turn solenoid at each rodposition.

Although FIG. 1 illustrates a solenoid weaving pattern having only aone-turn row solenoid and only a one-turn column solenoid at each rodposition, it is to be understood that additional solenoid turns may beprovided simply by repeating the weaving shown in FIG. 3 for each rowand/or column as many times as desired, and connecting the weavings forrespective rows and columns in series. FIG. 4, for example, illustratesa portion of a woven solenoid rod array having a three-turn row solenoidand a three-turn column solenoid formed at each rod position using thesolenoid weaving technique of the present invention. The spacing betweenweavings is exaggerated in FIG. 4, as is also done in other figures, forthe sake of clarity. Preferably, the multiple row and column weavingsare intermixed as illustrated in FIG. 4. Also, the multiple weavings foreach row (or column) may be connected in series using a single unbrokenwore I8 merely by using the wire from each previous row (or column) toform the weaving for the next row, as illustrated by the wire portions180 in FIG. 4, and as illustrated in FIG. 5 for a typical row.

It is also to be understood that additional solenoid windings for a rowor column may be provided in the same manner as additional turns, exceptthat, in this case, the additional weavings would be connected to theirappropriate respective circuitry, rather than being connected in serieswith the other weavings, as illustrated in FIG. 6 for a typical row inwhich numerals 23 and 24 indicate two separate row weavings, eachweaving providing a one-turn solenoid at each rod position.

From the description so far it should be evident that the use of thesolenoid weaving pattern for providing solenoids for the rods, as justdescribed, permits the rods to be placed very much closer together thanif the solenoids were wound individually, as in the aforementionedpatent and patent applications. This is because, with presently knownwinding techniques (as disclosed, for example, in US. Pat. No. 3,279,708issued Oct. I8, 1966 a relatively large spacing must be provided inorder to permit solenoids to be individually wound at each rod position.0n the other hand, as will be apparent from FIGS. 1, 3 and 4, thesolenoid weaving pattern of the present invention requires a rod spacingvery little more than the diameter of the wire l8, so that rod spacingis now dictated primarily by electrical and magnetic considerations,rather than by winding limitations.

An additional advantage of the solenoid weaving pattern of the presentinvention is that the more compact rod array made possible therebypermits higher speed operation, first, because the rows and columns arecloser together and thus reduce line inductance and propagation times,and second, because a more uniform array results which permits betternoise cancellation.

So far, the solenoid weaving technique of this invention has beenillustrated only in connection with providing the series connectedsolenoids for a row or column. However, this solenoid weaving techniqueis also applicable for providing the solenoid windings for an arrayconstituting a digit plane in which all solenoids are connected inseries, as illustrated, for example, in FIG. 7 in which a singleunbroken wire 18 is used throughout the array. FIG. 8 illustrates oneway in which a two-turn solenoid can be provided at each rod position inthe array of FIG. 7 by forming a double weaving in each row beforeproceeding to the next row, whereby the entire weaving for the array canbe accomplished using the single unbroken wire 18.

It will be understood that the digit plane solenoid weaving patternillustrated in FIGS. 7 and B may be substituted for either of the rowand column weavings in the array of FIG. I, or added thereto, withoutdetracting from the rod density capability, since this digit planeweaving pattern may merely be woven over the row and column weavings, orintermixed therewith, as desired.

FIGS. 9 and I0 also illustrate possible digit plane solenoid weavingpatterns in accordance with the invention, with the additional featurethat the digit plane weaving is divided into two like weaving patterns(32 and 34 in FIG. 9 and 42 and 44 in FIG. 10) suitable for use inobtaining common mode rejection by suitable connection to a senseamplifier transformer 50. It will be understood that multiturn solenoidwindings can be provided for the arrays of FIGS. 9 and II] by using therow weaving arrangement of FIG. 8.

It will also be understood that although only single rod arrays have sofar been considered herein, the solenoid weaving technique of theinvention may also be employed in connection with a three-dimensionalrod matrix, such as disclosed in the aforementioned US. Pat. No.3.l34,965. The manner in which this may be accomplished in illustratedin FIG. 11, which illustrates a three-dimensional matrix comprised of aplurality of similar plates 10 stacked with their apertures 10a alignedand suitably spaced by spacers 2B. Pins 30 and nuts 31 pass throughsuitably provided aligned holes in plates 10 and spacers 28 to hold thematrix together. Each of the magnetic rods 12 (only one of which isillustrated in FIG. II for the sake of clarity) is made of sufficientlength to pass through its respective aligned apertures 10a in all ofthe stacked plates 10, and each rod 12 may or may not have a coaxialwinding 25 provided thereon, depending on the memory organizationemployed.

Each of the plates I0 in FIG. II is constructed as illustrated in FIG. Iand may contain any desired combination of the various possible solenoidweaving patterns previously illustrated herein. For example, each plate10 may contain the row and column three-turn solenoid weavings forcoincident selection, as illustrated in FIG. 4, with the addition of thedigit plane winding of FIG. 9 for sensing purposes. Alternatively, eachplate 10 may contain merely the three-turn solenoid row weavingsillustrated in FIG. 5, with digit windings being provided by the coaxialwinding 25 on each rod I2, in which case the coaxial windings serve asboth digit and sense windings. As a further example, each plate 10 maymerely contain the digit plane solenoid weaving illustrated in FIG. 9with multiple turns provided as in FIG. 8, and the coaxial winding oneach rod 12 may then be used as the remaining winding. These examplesare merely exemplary, and others are possible, depending on theparticular memory organization employed.

Accordingly, it is to be understood that the present invention is notlimited to the particular embodiments disclosed herein, but is intendedto include all modifications, variations, and uses coming within thescope of the invention as defined in the appended claims.

What I claim is:

1. In a rod memory array, a plurality of spaced parallel bistablemagnetic rods arranged in a line, and a solenoid weaving patterncoupling said rods and formed in a plane perpendicular to the axisthereof, said solenoid weaving pattern comprising: a first insulatedconductive wire woven from rod to rod in a given line starting with aninitial rod at one end of said line to a rod at the other end of saidline and returning to the initial rod of said line and repeating thispattern for other lines of rods, so that said wire passes by adjacentrods in a given line on opposite sides thereof to produce a half-turnsolenoid for each rod in said given line which is in series with thesolenoids of all of the other rods in said given line; and a secondinsulated conductive wire woven in the same manner as said firstinsulated conductive wire said woven pattern being composed of at leasttwo circuits per plane, each of said two circuits having terminalsconnected to separate coils of a sense amplifiertransformer; and saidmagnetic rods having at least one sensedigit line coupled to saidmagnetic rods over the length of each magnetic rod.

2. In a rod memory array, a plurality of spaced parallel bistablemagnetic rods, and a solenoid weaving pattern coupling said rods andformed in a plane perpendicular to the axes thereof, said solenoidweaving pattern comprising at least one insulated conductive wire wovenfrom rod to rod forming a series string so that said wire passes byadjacent rods in a row on opposite sides thereof to produce a pluralityof series-connected half-turn solenoids coupled to respective ones ofsaid plurality of rods,

said magnetic rods having at least one sensedigit line coupled to eachof said magnetic rods over the length of each magnetic rod, a firstplurality of rows of solenoids are connected in series to form a firstseries string and a second plurality of rows of solenoids are connectedin series to form a second series string, and a transformer to whichsaid first and second series strings are connected in common modefashion.

3. In a rod memory array, a plurality of parallel bistable magnetic rodseach having a diameter of less than 50 mils and arranged in closelyspaced rows and columns, and a solenoid weaving pattern coupling saidrods and formed in a plane perpendicular to the axis thereof, saidsolenoid weaving pattern comprising a plurality of row solenoid weavingsand a plurality of column solenoid weavings coupling respective rows andcolumns in said array, each row and column weaving comprising a firstinsulated conductive wire woven from rod to rod so that said wire passesby adjacent rods on opposite sides thereof and a second insulatedconductive wire woven in the same manner as said first wire except thatsaid second wire passes by each rod on the opposite side from said firstwire.

4. ln a rod memory array, a plurality of parallel magnetic rods eachhaving a diameter of less than 50 mils, each rod comprising an innersubstrate having a thin bistable magnetic film deposited thereon, asupporting plate perpendicular to the axis of said rods and havingapertures in which respective rods are disposed in closely spaced rowsand columns, and a solenoid weaving pattern affixed to said plate andformed in a plane parallel thereto, said solenoid weaving patterncomprising a plurality of row weavings and a plurality of columnweavings coupling respective rows and columns in said array, each rowand column weaving comprising an insulated conductive wire woven fromrod to rod starting with a rod at one end and ending with a rod at theother end so that said wire passes by adjacent rods on opposite sidesthereof and after being looped around the rod at said other end beingwoven in the reverse direction back to said first end, the weaving ineach direction being such that said wire passes adjacent rods onopposite sides thereof with the wire for weavings in differentdirections being on opposite sides of each rod.

5. In a rod memory array, a plurality of parallel magnetic rods eachhaving a diameter of less than 50 mils, each rod comprising an innersubstrate having a thin bistable magnetic film deposited thereon, asupporting plate perpendicular to the axes of said rods and havingapertures in which respective rods are disposed in closely spaced rowsand columns, and a solenoid weaving pattern affixed to said plate andformed in a plane parallel thereto, said solenoid weaving patterncomprising a plurality of row weavings and a plurality of columnweavings coupling respective rows and columns in said array, each rowand column weaving comprising an insulated conductive wire woven fromrod to rod starting with a red at one end and ending with a rod at theother end and after being looped around me rod at said other end beingwoven in the reverse direction back to said first end and then beinglooped around the rod at said first end and being woven to said otherend and then being woven back to said first end, the weaving in eachdirection being such that said wire passes by adjacent rods on oppositesides thereof with the wires for weavings in different directions beingon opposite sides of each rod.

6. In a rod memory array, a plurality of parallel bistable magnetic rodseach having a diameter of less than 50 mils, each rod comprising aninner substrate having a thin bistable m netic film de osited thereon, asu ortin late er endigi ilar to the axe; of said rods and hatfi g aperti tres iii which respective rods are disposed in closely spaced rowsand columns, and a solenoid weaving pattern affixed to said plate andformed in a plane parallel thereto, said solenoid weaving patterncomprising a plurality of row weavings and a plurality of columnweavings coupling respective rows and columns in said array, each rowand column weaving comprising a first plurality of insulated conductivewires woven from rod to rod so that each wire of said first pluralitypasses by adjacent rods on opposite sides thereof and a second pluralityof insulated conductive wires woven in the same manner as said firstplurality except that the wires of said second plurality pass by eachrod on the opposite side from the wires of said first plurality.

7. The invention in accordance with claim 6, wherein the wires of saidfirst plurality are connected to corresponding wires of said secondplurality at the ends of each row and column so as to form a pluralityof series-connected multiturn solenoids for each row and column in whicheach rod has a corresponding multiturn row solenoid and a correspondingmultiturn column solenoid coupled thereto.

8. The invention in accordance with claim 6, wherein the wires of saidrow weavings are intermixed with the wires of said column weavings.

9. The invention in accordance with claim 8, wherein the intermixing ofrow and column wires is in an alternating manner.

1. In a rod memory array, a plurality of spaced parallel bistablemagnetic rods arranged in a line, and a solenoid weaving patterncoupling said rods and formed in a plane perpendicular to the axisthereof, said solenoid weaving pattern comprising: a first insulatedconductive wire woven from rod to rod in a given line starting with aninitial rod at one end of said line to a rod at the other end of saidline and returning to the initial rod of said line and repeating thispattern for other lines of rods, so that said wire passes by adjacentrods in a given line on opposite sides thereof to produce a half-turnsolenoid for each rod in said given line which is in series with thesolenoids of all of the other rods in said given line; and a secondinsulated conductive wire woven in the same manner as said firstinsulated conductive wire said woven pattern being composed of at leasttwo circuits per plane, each of said two circuits having terminalsconnected to separate coils of a sense amplifiertransformer; and saidmagnetic rods having at least one sensedigit line coupled to saidmagnetic rods over the length of each magnetic rod.
 2. In a rod memoryarray, a plurality of spaced parallel bistable magnetic rods, and asolenoid weaving pattern coupling said rods and formed in a planeperpendicular to the axes thereof, said solenoid weaving patterncomprising at least one insulated conductive wire woven from rod to rodforming a series string so that said wire passes by adjacent rods in arow on opposite sides thereof to produce a plurality of series-connectedhalf-turn solenoids coupled to respective ones of said plurality ofrods, said magnetic rods having at least one sense-digit line coupled toeach of said magnetic rods over the length of each magnetic rod, a firstplurality of rows of solenoids are connected in series to form a firstseries string and a second plurality of rows of solenoids are connectedin series to form a second series string, and a transformer to whichsaid first and second series strings are connected in common modefashion.
 3. In a rod memory array, a plurality of parallel bistablemagnetic rods each having a diameter of less than 50 mils and arrangedin closely spaced rows and columns, and a solenoid weaving patterncoupling said rods and formed in a plane perpendicular to the axisthereof, said solenoid weaving pattern comprising a plurality of rowsolenoid weavings and a plurality of column solenoid weavings couplingrespective rows and columns in said array, each row and column weavingcomprising a first insulated conductive wire woven from rod to rod sothat saId wire passes by adjacent rods on opposite sides thereof and asecond insulated conductive wire woven in the same manner as said firstwire except that said second wire passes by each rod on the oppositeside from said first wire.
 4. In a rod memory array, a plurality ofparallel magnetic rods each having a diameter of less than 50 mils, eachrod comprising an inner substrate having a thin bistable magnetic filmdeposited thereon, a supporting plate perpendicular to the axis of saidrods and having apertures in which respective rods are disposed inclosely spaced rows and columns, and a solenoid weaving pattern affixedto said plate and formed in a plane parallel thereto, said solenoidweaving pattern comprising a plurality of row weavings and a pluralityof column weavings coupling respective rows and columns in said array,each row and column weaving comprising an insulated conductive wirewoven from rod to rod starting with a rod at one end and ending with arod at the other end so that said wire passes by adjacent rods onopposite sides thereof and after being looped around the rod at saidother end being woven in the reverse direction back to said first end,the weaving in each direction being such that said wire passes adjacentrods on opposite sides thereof with the wire for weavings in differentdirections being on opposite sides of each rod.
 5. In a rod memoryarray, a plurality of parallel magnetic rods each having a diameter ofless than 50 mils, each rod comprising an inner substrate having a thinbistable magnetic film deposited thereon, a supporting plateperpendicular to the axes of said rods and having apertures in whichrespective rods are disposed in closely spaced rows and columns, and asolenoid weaving pattern affixed to said plate and formed in a planeparallel thereto, said solenoid weaving pattern comprising a pluralityof row weavings and a plurality of column weavings coupling respectiverows and columns in said array, each row and column weaving comprisingan insulated conductive wire woven from rod to rod starting with a rodat one end and ending with a rod at the other end and after being loopedaround the rod at said other end being woven in the reverse directionback to said first end and then being looped around the rod at saidfirst end and being woven to said other end and then being woven back tosaid first end, the weaving in each direction being such that said wirepasses by adjacent rods on opposite sides thereof with the wires forweavings in different directions being on opposite sides of each rod. 6.In a rod memory array, a plurality of parallel bistable magnetic rodseach having a diameter of less than 50 mils, each rod comprising aninner substrate having a thin bistable magnetic film deposited thereon,a supporting plate perpendicular to the axes of said rods and havingapertures in which respective rods are disposed in closely spaced rowsand columns, and a solenoid weaving pattern affixed to said plate andformed in a plane parallel thereto, said solenoid weaving patterncomprising a plurality of row weavings and a plurality of columnweavings coupling respective rows and columns in said array, each rowand column weaving comprising a first plurality of insulated conductivewires woven from rod to rod so that each wire of said first pluralitypasses by adjacent rods on opposite sides thereof and a second pluralityof insulated conductive wires woven in the same manner as said firstplurality except that the wires of said second plurality pass by eachrod on the opposite side from the wires of said first plurality.
 7. Theinvention in accordance with claim 6, wherein the wires of said firstplurality are connected to corresponding wires of said second pluralityat the ends of each row and column so as to form a plurality ofseries-connected multiturn solenoids for each row and column in whicheach rod has a corresponding multiturn row solenoid and a correspondingmultiturn column solenoid coupled thereto.
 8. The invention inaccordance with claim 6, wherein the wires of said row weavings areintermixed with the wires of said column weavings.
 9. The invention inaccordance with claim 8, wherein the intermixing of row and column wiresis in an alternating manner.